Many people wear equipment and clothing designed to protect them from temperature extremes, and to regulate the temperature of their body. Professionals such as firefighters and athletes most often use this type of protective equipment and clothing, although use of such clothing is by no means limited to these users. For example, firefighters are required to wear heavy clothing that provides protection from extreme heat. While the heavy clothing worn by firefighters serves an important function by shielding the user from heat, it similarly is very warm and can lead to the wearer becoming overheated. Likewise, athletes such as football and hockey players, and racecar drivers wear heavy protective gear that provides essential protection, but which may lead to overheating. This is especially true with football players who often play in hot, humid conditions. Just as heavy protective clothing and equipment serves a necessary purpose, in doing so it can contribute to overheating, which in extreme cases may be a dangerous condition.
Various ventilation systems worn by athletes and the like have been designed for alleviating overheating caused by protective clothing and equipment. For example, U.S. Pat. No. 4,738,119 to Zafred, U.S. Pat. No. 5,970,519 to Weber, and U.S. Pat. No. 6,596,019 to Turner et al. each describe ventilation systems that are worn by individuals who can benefit by keeping body temperature regulated. Each of the cooling apparel systems described in these patents requires a source of a fluid that may be supplied to the apparel system. In the '119 patent the apparel device is connected to a source of liquid carbon dioxide. The cooling garment is charged with liquid carbon dioxide, which converts to a solid phase in the garment, and the garment is then disconnected from the carbon dioxide source. The solid carbon dioxide in the garment sublimates while the garment is worn to thereby cool the user. The '519 patent provides a method for connecting the garment to a source of relatively dry air—the air flows through an air permeable layer in the garment to cool the wearer. Air may be supplied to the garment from a pressurized canister mounted to a wearer's belt, a remote supply such as a compressor, or a portable blower. The '019 patent describes a ventilation system having an air bladder that receives air from a compressor to supply warm or cooled air to the ventilation system.
There is a need for improved air delivery systems designed for use with ventilation systems worn by individuals to regulate body temperature.